A 125GeV Higgs may indicate something much more exciting: the radion.

The good folks at the LHC have not been shy about sharing their results. Indeed, at the end of last year, the bigwigs at CERN called a press conference to announce that they hadn't found the Higgs boson yet, but they were starting to see some signals that might be the Higgs. If only all of us in research could get away with progress reports like that.

OK, that was a very cynical opening to a story that shows the benefits of such openness. The signal seen by the LHC's CMS and ATLAS detectors hinted at a Higgs Boson with a mass in the range of 124-126GeV. But buried in the details are some numbers that, if they hold up, will be impossible to accommodate in the standard model of physics. What does any good theoretical physicist do in these circumstances? Plug the numbers into their favorite model to see if it is still in the running. Something that could not be done had CERN not been so open about its preliminary results.

Get off that branch before it breaks

The details of obtaining the Higgs' mass range contains a huge amount of statistics and modeling of particle production. It is not just that these collisions produce huge numbers of different particles, but that these particles can decay to different particles, and collisions between particles can produce different collision products. You can think of each collision as a measurement on a quantum system, where there is more than one possible result. But the probabilities of each result are governed by the underlying details of the collision.

Unluckily (or, perhaps, luckily), the detectors don't see any of these intermediate particles. Instead, they only detect the relatively stable end products—basically, the LHC detects electrons, positrons, muons, and radiation. It is then a case of figuring out, from large numbers of collisions, what paths were involved in creating the particles we do see.

Each particle could have arrived by a number of different pathways through intermediate particles. Some pathways are more common than others, so we end up with what are referred to as branching ratios. Adding Higgs production to the mix will enhance some branching ratios and suppress others. Luckily, the standard model of physics tells us how to calculate these changes.

This is where the results from CERN are important. The mass of the Higgs Boson fits quite nicely with the standard model, but the branching ratios, according to Cheung and Yuan, are going to be difficult to accommodate. What the CMS results show is that one particular branch must be enhanced by Higgs production, and two others are suppressed. But the standard model suggests otherwise (though it should be pointed out that the data is not certain enough to be clear that the standard model is wrong).

New Physics

This may actually come as a relief to many, because nothing new has been turned up by the LHC so far. Physicists have many proposals for physics beyond the standard model—all motivated by the desire to resolve conflicts between general relativity and quantum electrodynamics. And now everyone is waiting for data from the LHC to help decide which models best reflect the world.

The most popular of these models involves giving every particle a heavy partner to satisfy certain symmetries—the model is called supersymmetry. It turns out that there are a few ways to make supersymmetric models, but physicists have generally favored the simplest. Except that if that model were right, the LHC should have started to see signs of the lightest particles predicted by supersymmetry. Which it hasn't.

So the field appears to be rather open at the moment, with every new data point eliminating someone's favorite model while providing tantalizing hints that someone else's might be right. In this case, the model that's still in the running is a relative of supersymmetry, involving one extra dimension and a lot of new, heavier particles. Now, the production of one particle, called the radion, would have the effect of simultaneously enhancing one branching ratio while suppressing others, in agreement with the LHC data.

This paper can't really come to any clear conclusions because the data from the LHC is not certain enough to support anything definitive. But what this points to is the difficulty in understanding and interpreting data from modern particle accelerators. Even if, in the next year, the LHC pins the Higgs down to 125GeV, it is unlikely that the data will be clear enough to pick a single model for physics beyond the standard model—if, indeed, it provides any support for such a model at all.

I also think that particle physicists get to use the coolest names for their particles.

Chris Lee
Chris writes for Ars Technica's science section. A physicist by day and science writer by night, he specializes in quantum physics and optics. He lives and works in Eindhoven, the Netherlands. Emailchris.lee@arstechnica.com//Twitter@exMamaku

I hope the LHC just explodes the standard model, and the next theory of physics does away with the icky 'renormalization' hacks. This is so exciting! It's like a major new release of an OS for the entire universe.

I hope the LHC just explodes the standard model, and the next theory of physics does away with the icky 'renormalization' hacks. This is so exciting! It's like a major new release of an OS for the entire universe.

I LOVE that analogy! Personally, I think we are near one of those "eureka" moments when everyone in physics does a facepalm and says "Oh! We have been looking at things all wrong!"

It's these kind of moments that have led to some of the most astounding advances in science...when someone finds a result that comes out of left field and redefines EVERYTHING! Exciting stuff!

Also where does dark matter, dark energy, and dark flow come in?if dark matter is matter it'll need some particals to make it?

If dark energy is energy then won't it need some boson to enable it?

and no clue on dark flow.

IMO the LHC should also help find these particles.

These are just dark spots in our understanding of physics.Dark matter is what we are most certain of and there are many possible candidates. Right now we call them WIMPS or Weakly Interacting Massive Particles. Neutrinos are even a candidate for these as well. We can see evidence for dark matter in rotational speeds of the outer rims of Galaxy and the gravitational centers of massive galaxy collisions. Dark Energy is something that it is not understood all that well. It is here to explain the expansion and acceleration of the universe. It could just be a property of space(or cost of) as Albert Einstein thought and later decanted with the Cosmological Constant. Or it could be a result of a tensor(Stress Energy Tensor) if you will like the Universe being a Tensor 0 and the Gravity be a tensor 2 and mass being a tensor 1. Its effect is calculable though and it requires a lot of energy to expand the universe like that.Dark Flow is less likely now and it is basically a description of a general direction of the universe. Its explanation was that the universe was attracted to another universe. Its a fringe idea with a some supporters but far from the supporting evidence of Dark Energy and Dark Matter. I wouldn't put this one in the same discussion as those two. Its completely unrelated and the only thing it shares is that it has the word Dark in it to describe unknown observations.

As I understand it, there's such a massive deluge of data from the LHC that programs had to be written to cull out the supposed chaff to a level that could be investigated by the scientists using more exacting programs. If this is so, then to some extent we might be seeing only data that clusters close to what we're looking for. Maybe the *Answer* is in the chaff. Too bad like Dark Matter we can't figure out a way to access it.

As I understand it, there's such a massive deluge of data from the LHC that programs had to be written to cull out the supposed chaff to a level that could be investigated by the scientists using more exacting programs. If this is so, then to some extent we might be seeing only data that clusters close to what we're looking for. Maybe the *Answer* is in the chaff. Too bad like Dark Matter we can't figure out a way to access it.

+1 that the answer is in the chaff. Any time you restrict your data, you confine your options to what you think you already know.

Also where does dark matter, dark energy, and dark flow come in?if dark matter is matter it'll need some particals to make it?

If dark energy is energy then won't it need some boson to enable it?

and no clue on dark flow.

IMO the LHC should also help find these particles.

These are just dark spots in our understanding of physics.Dark matter is what we are most certain of and there are many possible candidates. Right now we call them WIMPS or Weakly Interacting Massive Particles. Neutrinos are even a candidate for these as well. We can see evidence for dark matter in rotational speeds of the outer rims of Galaxy and the gravitational centers of massive galaxy collisions. Dark Energy is something that it is not understood all that well. It is here to explain the expansion and acceleration of the universe. It could just be a property of space(or cost of) as Albert Einstein thought and later decanted with the Cosmological Constant. Or it could be a result of a tensor(Stress Energy Tensor) if you will like the Universe being a Tensor 0 and the Gravity be a tensor 2 and mass being a tensor 1. Its effect is calculable though and it requires a lot of energy to expand the universe like that.Dark Flow is less likely now and it is basically a description of a general direction of the universe. Its explanation was that the universe was attracted to another universe. Its a fringe idea with a some supporters but far from the supporting evidence of Dark Energy and Dark Matter. I wouldn't put this one in the same discussion as those two. Its completely unrelated and the only thing it shares is that it has the word Dark in it to describe unknown observations.

With Dark Matter wouldn't it be possible that it has some partical might be unique to it outside of the standard model? and then might th LHC at some point make some dark matter?

I agree about "dark Flow" when we can't really see the WHOLE thing how can we know where its going, so what we can see might just be our part of it.

As I understand it, there's such a massive deluge of data from the LHC that programs had to be written to cull out the supposed chaff to a level that could be investigated by the scientists using more exacting programs. If this is so, then to some extent we might be seeing only data that clusters close to what we're looking for. Maybe the *Answer* is in the chaff. Too bad like Dark Matter we can't figure out a way to access it.

+1 that the answer is in the chaff. Any time you restrict your data, you confine your options to what you think you already know.

+2

If you can't investigate the full data you should look for a way that you could not reduce the data to fit you're preconviced ideas.

LHC is too weak to provide these answers, it can't really find Higgs, it is unsaid but well known. We need a space based collider to provide enough energy. I'm hoping they build a space based gravity interferometer first, studying gravity waves seems the more likely place to learn about anti-gravity/dark matter/dark energy.

The Higgs particle will go the same way as the Graviton.That 'particles' are only Energy must one day be accepted.All fundamental properties will one day be explained when it is recognised that only wave functions are involved. Each individual 'particle' carries all its own physical properties, including Mass, according to Wave mechanics.The double slit experiment, allied with Dirac, is more than enough evidence.

As I understand it, there's such a massive deluge of data from the LHC that programs had to be written to cull out the supposed chaff to a level that could be investigated by the scientists using more exacting programs. If this is so, then to some extent we might be seeing only data that clusters close to what we're looking for. Maybe the *Answer* is in the chaff. Too bad like Dark Matter we can't figure out a way to access it.

+1 that the answer is in the chaff. Any time you restrict your data, you confine your options to what you think you already know.

+2

If you can't investigate the full data you should look for a way that you could not reduce the data to fit you're preconviced ideas.

The LHC triggering and prescaling setup is probably the single most obsessed-over, quintuple-checked, thoroughly-vetted experimental setup in the history of science, no exaggeration. Every theorist on Earth pores over the announced cuts to make sure his/her favorite model won't be untestable, and the triggering is changed if someone points out a possible flaw, and this has been going on since before the LHC was announced, in anticipation of a future powerful collider. Just in case they're getting it wrong, they still keep a tiny fraction of the boring events and analyze them periodically to make sure nothing suspicious is happening in them. There is no reason to suspect that any of these dropped events are interesting, since all of the uninteresting processes were thoroughly studied decades ago, and no evidence so far that they're not exactly as boring as they are thought to be.

To clarify, events are thrown out only if they look like things we've seen before. It's not something like "oh this doesn't look like what supersymmetry is supposed to look like, toss it." It's more "yup, the 30 billionth gluon splitting event in the last 20 seconds, don't bother saving it." They simply can't write the amount of data per second required to save every event. There is no storage technology with a high enough bit rate.

"Indeed, at the end of last year, the bigwigs at CERN called a press conference to announce that they hadn't found the Higgs boson yet, but they were starting to see some signals that might be the Higgs. If only all of us in research could get away with progress reports like that."

Um -- that was kind of a forced situation. Like the neutrinos debacle, the point was to cut off the media feeding frenzy about a poorly-understood and unreleased result before it turned fractally stupid.

As I understand it, there's such a massive deluge of data from the LHC that programs had to be written to cull out the supposed chaff to a level that could be investigated by the scientists using more exacting programs. If this is so, then to some extent we might be seeing only data that clusters close to what we're looking for. Maybe the *Answer* is in the chaff. Too bad like Dark Matter we can't figure out a way to access it.

+1 that the answer is in the chaff. Any time you restrict your data, you confine your options to what you think you already know.

+2

If you can't investigate the full data you should look for a way that you could not reduce the data to fit you're preconviced ideas.

The LHC triggering and prescaling setup is probably the single most obsessed-over, quintuple-checked, thoroughly-vetted experimental setup in the history of science, no exaggeration. Every theorist on Earth pores over the announced cuts to make sure his/her favorite model won't be untestable, and the triggering is changed if someone points out a possible flaw, and this has been going on since before the LHC was announced, in anticipation of a future powerful collider. Just in case they're getting it wrong, they still keep a tiny fraction of the boring events and analyze them periodically to make sure nothing suspicious is happening in them. There is no reason to suspect that any of these dropped events are interesting, since all of the uninteresting processes were thoroughly studied decades ago, and no evidence so far that they're not exactly as boring as they are thought to be.

To clarify, events are thrown out only if they look like things we've seen before. It's not something like "oh this doesn't look like what supersymmetry is supposed to look like, toss it." It's more "yup, the 30 billionth gluon splitting event in the last 20 seconds, don't bother saving it." They simply can't write the amount of data per second required to save every event. There is no storage technology with a high enough bit rate.

Let's put it another way.

What makes you (DarkLogix and OldFortraner) think you can evaluate anything at all? Ask how it's done, if you're genuinely interested.

When I discuss this with real scientists, that's the question they have... and it's one that's easily answered.

Believe that five billion dollars weren't spent without thinking this through. There's a century of work in this field that this builds on.

It all seems premature, since people directly involved in the Higgs search points out that1) we haven't seen the Higgs yet - it will happen earliest this year.2) we haven't verified that it is a standard Higgs or not - in the first case it will take a few years, in the latter case it may take more than a few years.

If it _is_ a lone standard Higgs, it will even more interesting. A 124-126 GeV standard Higgs is quasistable over a life time much longer than our current universe age or ~ 10^100 years.

This is a familiar theme. It was once suggested that matter is quasistable, protons could decay in ~ 10^30 years, but experiments showed they did not. Then it was suggested that spacetime could decay in ~ 10^100 year, as a Big Rip would tear it, but experiments showed that the cosmological constant is in place which prohibits it.

And now the vacuum of fields are suggested as quasistable, as when the Higgs goes it goes. But this time experiments _suggests_ it.

Such an outcome would most likely be predicted by environmental selection, in the same way that it predicts the cosmological constant. Too short lifetimes of universes and there are no observers. According to Bousso e.s. predicts 6 parameters. This could be the 7th.

Dark energy and dark matter are parts of standard cosmology, and they are both observable by themselves. (As opposed to, say, inflation which isn't yet as significant an observation.)

- Dark energy is predicted by a cosmological constant, which in turn is predicted by environmental selection. It looks like a residual of vacuum fields as seen in a cosmological setting.

I don't agree with redspear2, it is a very dilute energy density many, many, many orders of magnitude less than expected by a straight estimate of vacuum fields. (Famously, the worst estimate in physics, the cc is ~ 10^120 times weaker than expected.)

- Dark matter predicts all structure formation from universe scale (the Bolshoi simulation) to recently galaxies (the Eris simulation). It has turned out to be the missing piece to predict galaxy structure, and it is the only way to predict unique cluster collision mass observations by gravitational lensing.

Today we can observe dark matter better than we could observe atoms at the time everyone accepted them. The analogy is that chemical reaction ratios predicted atoms in the same way that standard cosmology predicts dark matter in order to fit the observations, that brownian motion predicted atom interactions in the same way that dark matter predicts galaxy structure interactions, and that AFMs now image atoms on surfaces in the same way that gravity lensing images dark matter in cluster collisions.

The brownian motion and its prediction of molecular motion by Einstein was that clinched the case for atom theory. So dark matter theory has passed that point in very short order. (Atom theory was millenniums or centuries old depending on your view, dark matter was merely some 50 years before the first cluster observations.)

Supersymmetry, say, predicts dark matter.

- Dark flow never existed. Many times over the entire set of standard cosmology data has rejected the claim, which was based on cherry-picked data.

- Dark energy is predicted by a cosmological constant, which in turn is predicted by environmental selection. It looks like a residual of vacuum fields as seen in a cosmological setting.

I don't agree with redspear2, it is a very dilute energy density many, many, many orders of magnitude less than expected by a straight estimate of vacuum fields. (Famously, the worst estimate in physics, the cc is ~ 10^120 times weaker than expected.)

I am just curious which part? I only mentioned the cosmological constant because it was the first hint of an continuing expansion. Einstein was arguing against the big bang and he was trying to balance out Gravity to create a balance universe. We all know that was wrong and even Einstein regretted it.The force itself would have to be very very weak. much weaker than the already weak gravity or else it would overpower gravity. What I meant by a lot of energy is that it would as whole account for most of the universe energy. On a side note I really don't like it when people mix Dark matter/dark energy and dark flow together. Because IMO dark flow doesn't even belong in the same discussion.

their "openness" wouldn't have anything to do with the kagillion tax dollars they used to build the LHC, would it?

Firstly LHC is European project so they didn't tax any US dollars.

Secondly the whole budget of LHC is 7.5 billion euros. About 9 B2 bombers. There are about 20 B2 bombers in service.

Check facts before posting silly comments,

Right back at you.

The US isn't part of CERN, but three of our national physics laboratories (FermiLab, Brookhaven, and Lawrence Berkley) are working with CERN for the LHC. The national science foundation contributed around $20m/year during the earlier parts of its development (couldn't find current numbers); it's not clear if this money was used to pay for the work the national laboratories did or of their funding came from a different line item. The $200M the NSF was budgeting to spend on it by 2010 is only a small fraction of the cost; but we are a player.

A new study has found no trace of the mysterious substance known as dark matter around the sun, adding a twist to current theories, researchers say....According to widely accepted theories, the neighborhood around the sun should be filled with dark matter, with billions of these particles rushing through us every second. However, the most accurate study yet of motions of stars in the Milky Way now has found no evidence for dark matter in a large volume around the sun.

"Our results contradict the currently accepted models — the mystery of dark matter has just become even more mysterious," said study lead author Christian Moni Bidin, an astronomer at the University of Concepción in Chile....Dark matter models had predicted there should be about 0.9 to 2.2 pounds (0.4 to 1 kilograms) of dark matter in a volume the size of the Earth in the sun's part of the galaxy. However, these new findings suggest there is at most 0.15 pounds (70 grams) of dark matter in that volume in our part of the Milky Way galaxy.

"Despite the new results, the Milky Way certainly rotates much faster than the visible matter alone can account for, so if dark matter is not present where we expected it, a new solution for the missing mass problem must be found," Moni Bidin said.

Basically it is the last hold out in particle's that were predicted in the Standard Model of particle physics ( http://en.wikipedia.org/wiki/Standard_Model ). All the others were predicted and then discovered, The is Higgs is also arguably the most important one as it... if found will be the particle that gives all other particle's mass.